Cannot Add New Field as Display Format

I have added the countries field to my "article" content type, however I am unable to find a way to make the country display as a link at the bottom of each article. The display formats only include those fields that came default with the module.

My idea was to add a "link" field to the countries module and configure it with tokens to point to a views page that filters content by country. However, my new field just doesn't show up as a display format, or as a suffix option for the "country icon" display format.

Help much appreciated!